The purpose of the proposed project is to conduct a comprehensive, comparative analysis of the use of health services by elderly Anglo, Black, Cuban, Puerto Rican, and Mexican Americans. The conceptual framework involves a modification of the behavioral model of health services utilization. The specific aims are to address the following research questions: (1) are the determinants of health services utilization the same or different (including the magnitude of their effects) for the five ethnic groups (i.e., Anglo, Black, Cuban, Puerto Rican, and Mexican Americans); (2) do the determinants of health services utilization differentially vary among 5 age groups (i.e., 45-54, 55-64, 65-74, 75-84, 85+) within each of the five ethnic groups; (3) does the effect of ethnicity depend on the degree of institutional completeness of the ethnic group in the health care institutions in the community; and, (4) are there universal chronological age markers for categorizing the health services utilization of the elderly, or do these markers need to be ethnicity-specific? The major source of data will be the 1976 through 1984 Health Interview Surveys. Pooling these surveys provides data on approximately 111,500 individuals aged 45 years or more and living in the 31 largest self-representing SMSA's, including about 95,000 Anglo, 12,000 Black, 1,500 Cuban, 1,100 Puerto Rican, and 1,900 Mexican Americans. Supplementary contextual information on the characteristics of the health care available, the communities, and their ethnic diversity will be merged from existing archives, including the 1980 Area Resources File, and the 1980 Census of the United States. Multiple regression and related analytic techniques will be used.